I disagree ... Get one done and play now. From reading about the new breakthroughs you have to dedicate a ds4 since it steals the bluetooth address and spoofs it. This is something you will always be able to do with the WD. Just because it has a bunch of wires coming out doesnt take away ds4 authentication functionality. I still use my xim2 as the controller for authentication on my edge.
On a side note, you cannot authenticate a ds4 twice on the same ps4 so im assuming you are dedicating a ds4 to the setup anyways.
#2... You can hook up a ds3 or xbox controller and use it in game. In other words, you do not lose a controller.
I've been playing War Thunder on the ps4 and being able to swap sticks (mode 2 for you rc geeks like me) via the WD has been priceless. Just swap a couple wires and viola.
The only reason not to do it is if you are tight on money, which is totally understandable. I understand we are possibly right around the corner from awesomeness but there is still no date.
The WD is a very cool device which is software upgradeable via the teensy.